The human ear pinna (the visible external structure of the ear) and the ear canal modify sound waves before they reach the ear drum. This is known as the pinna notch effect and plays a major role in psychoacoustics. The human brain processes the sound phase and pinna notch difference between the left and right ears and creates the perception of sound localization so that we can feel the location and the distance of the sound source relative to our head in three dimensional space. This is a well-researched science, and there exists known binaural microphone technology which uses a dummy ear replica or human head worn microphone to attempt to capture the psychoacoustic sound we experience in our normal hearing.
For example, U.S. Pat. No. 4,088,849 to Usami, et al. discloses a headphone unit incorporating microphones for binaural recording including a headphone having a pair of microphone-loudspeaker units interconnected by a clamping strap for holding the units against the ears of a wearer. The loudspeaker and a microphone of each unit are isolated acoustically from each other by an enclosure. The enclosure is formed with a generally semicylindrical surfaced portion to simulate the human earlap and a flat surface normal to the semicylindrical surface. The microphone is mounted on the flat surface with its main direction of acoustic sensitivity oriented to a dummy earlap to receive a sound wave reflected therefrom.
U.S. Pat. No. 4,308,426 to Kikuchi describes a dummy head for use in recording binaural sounds and includes a pick-up for the sounds in the form of two microphones. The head comprises a pair of simulated ears, each having a single smooth three-dimensional, curved surface extending radially in all directions so the inner surface of an auditory canal is continuous with the curved surface and the junction area between them is smoothly curved, to improve the frequency characteristics of the output signals of the microphones. The microphone is located in each ear.
U.S. Pat. No. 7,715,568 to Nakano teaches a binaural sound reproduction apparatus including a correction filter operable to filter an input sound signal that is recorded using a binaural recording microphone and to supply the filtered signal to a headphone, an adaptive filter to which the input sound signal is supplied, and a difference detector determining a difference between a sound signal that is obtained by collecting a sound reproduced by the headphone using a sound-collecting microphone that is the same as the binaural recording microphone, or that has a similar characteristic to that of the binaural recording microphone, and a sound signal output from the adaptive filter, and for transmitting the difference to the adaptive filter. The adaptive filter determines the inverse of a synthesis characteristic from the headphone to the sound-collecting microphone based on the input sound signal and the difference, and sets the determined characteristic as a characteristic of the correction filter.
United States Patent Application 20080002948 to Murata, et al. discloses a video-audio recording and reproducing apparatus with a built-in stereo microphone and an external microphone connection terminal. The external microphone connection terminal is connected to a binaural microphone to be attached to the ears of a photographer. When the binaural microphone is used to collect ambient sounds, an audio signal to be recorded on a recording medium is switched from an audio signal from the built-in stereo microphone to a binaural audio signal from the binaural microphone. The photographer puts the binaural microphone on his or her ears and collects ambient sounds around the photographer including a sound emanating from an object. The object is photographed with a camera unit. The recording medium records the binaural audio signal, a photographed video signal, and a binaural flag signal.
United States Patent Application 20090022343 to Van Schaack, et al. describes a pen based computing system that concurrently captures handwriting gestures and records audio using binaural recording. A binaural headset communicatively coupled to the smart pen device uses at least two microphones. A left microphone is placed in or near the left ear and the right microphone is placed in or near the right ear, each facing outward. Speakers are integrated into a shared housing with the microphones facing inward towards the ear canal to play back the audio recordings. By recording audio with microphones placed close to the ears, the system provides realistic sounding playback and allows users to more easily differentiate between multiple sources of audio.
United States Patent Application 20100104118 to Sasidharan, et al. teaches methods and systems of earpiece based binaural sound capturing and playback. In one embodiment, a method for recording and playback of a binaural sound includes receiving a record command for a binaural sound, and recording electrical data which correspond to the binaural sound captured through an associated binaural sound capturing system. Further, the associated binaural sound capturing system includes two earpieces for a right ear and a left ear for a user. Each of the two earpieces includes a housing and a speaker embedded in the housing facing an inner ear of the user. In addition, the each of the two ear pieces also includes a microphone embedded in the housing at an ear canal of the user for converting the binaural sound received by the ear canal to the electrical data. Furthermore, the method includes playing back the electrical data in response to a playback command.
The foregoing patents and patent applications reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents and applications is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents or applications disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.